Synchronized centrifugal clutch



Aug. 4, 1953 E. R. MAURER SYNCHRONIZED CENTRIFUGAL CLUTCH Original FiledFeb. 19, A1945 INVENTOR. '(Jwzv R. M2178?! ,375 BY l? /sfffaR/vfns.

Patented Aug. 4, 1953 SYNCHRONIZED CENTRIFUGAL CLUTCH Edwin R. Maurer,Detroit, Mich., assgnor to Chrysler Corporation, Highland Park, Mich., acorporation of Delaware Original application February 19, 1945, SerialNo. 578,631. -Divided and this application July 24, 1948, Serial No.40,566

9 Claims. 1

This invention relates to power transmitting drives providing a pawlclutch of the centrifugal type engageable to drivingly connect a drivingand a driven member. More particularly my invention has reference tocentrifugal pawl clutch mechanism providing means for controlling thepawl engagement, for example, whereby it may be made operably responsiveto certain predetermined conditions of operation of the drive structurewith which the clutch mechanism is associated. The present applicationis a division of my copending application Serial No. 578,631, filedFebruary 19, 1945, and now Patent Number 2,448,539, issued September '7,1949.

My invention will be illustrated as applied to a centrifugally actuatedpawl clutch mechanism for locking together against slip under certainconditions of vehicle operation a pair of fluid power transmittingelements, which clutch mechanism includes a driving member drivinglyassociated with one of said power transmitting elements, a driven memberdrivingly associated with the other of the power transmitting elements,a locking pawl carried by one of the members and operably responsive tocentrifugal force upon predetermined rotation of said one member forinterconnecting said clutch elements and means for preventing theoperation of the clutch mechanism for positively locking together thefluid power transmitting elements until the rotative speeds of theclutch members have been first brought to approximate synchronism.

An object of the invention therefore, is to provide an automaticallyoperable clutch mechanism with means operable in response to functioningof the power transmitting drive structure in which the clutch mechanismis incorporated for controlling engagement of the clutch mechanism.

Another object is to provide a centrifugal type pawl clutch mechanismfor an automotive vehicle drive structure with blocker means operableautomatically under certain conditions of vehicle functioning forpositively preventing engagement of the pawl.

A more particular object is the provision of engagement control meansfor a centrifugal pawl clutch comprising a frictionally driven balk ringhaving laterally projecting ngers for interlocking with the pawl duringasynchronous rotation of the driving and driven members of the clutch toprevent its engagement.

Other objects of my invention will be apparent from the followingdescription and the drawing wherein:

Fig` 1 is a sectional elevation of a portion of a transmission embodyingthe present invention;

Fig. 2 is a sectional view taken along the line 2-2 of Fig. 1; and

Fig. 3 is an elevational view of the control ring of my invention shownin perspective.

Referring to Figs. 1 and 2, it will be seen that there is illustrated afluid power transmitting device such as a uid coupling having animpeller I IJ provided with an annular ring I I by which it is carriedon a hub I2 which is fastened to an engine crankshaft I3 by means ofstuds I4 and nuts I5. The impeller includes a housing portion I6 whichencloses a runner II, the latter being welded to a hub I8 or fastenedthereto by bolts I9. A forward seal 20 and a rearward seal 2| preventleakage of the uid which is circulated in the passages formed by thevanes 22, as is common in the art. The runner hub I8 has a tubulardriven portion 23 by which drive is imparted to the input member of thevehicle transmission. This tubular portion as shown, pilots atransmission shaft 24. The impeller hub I2 serves as the pawl drivemember of a centrifugal clutch, it having a rearward pawl carrying coreportion 25 formed with a shoulder 26 and which is slotted to carry apair of pawls 21. The pawls are movable radially outwardly in responseto centrifugal force acting upon the pawls during rotation of theimpeller hub I2. The pawls 21 are an element of the centrifugal clutchand have ears 28 provided with recesses 29 for receiving a coilcompression spring 30 of predetermined force value which tends to keepthe pawls in retracted, that is, disengaged position. The pawls areshaped, as illustrated, and each has an integral tail portion 3| whichlies alongside a portion 32 of the head 33 of the pawl and acts as adragging connection between the pawl and the hub I2 as well as a guideto keep the pawls in position. The pawl carrying core 25 is providedwith rearwardly projecting annular segments 34, 35 which serve asguideways for the head 33 and tail 3I of the pawls and further providethe driving connection between the hub I2 and the pawls.

The pawls loosely embrace the core 25 and have sufficient clearance inslotted guideways 36 such that they can move radially outwardly underthe influence of centrifugal force or be retracted by the spring 30.This movement is limited in both directions by engagement of the innersurface 31 of the pawls with the shoulder 26 of the pawl core 25 or byabutment of the pawl ears 28 with the adjacent faces 38, 39 of theannular segments 34, 35 respectively, which form a slot 40 for receptionof the ear 28.

The springs 30 may be of any desired strength to produce the operatingcharacteristics desired,

engage the openings 42.

it being understood that the springs will keep the pawls in theillustrated retracted position until a predetermined speed of the drivehub I2 is reached whereupon centrifugal force will overcome the force ofthe springs and the pawls will tend to move radially outwardly asexplained below.

The runner hub I8 carries a bailie 40A for reducing the efciency of thecoupling at idling speed and for preventing surges and is formed With aforwardly projecting annular portion 4I constituting the driven memberof the centrifugal clutch. The portion 4I is provided withcircumferentially spaced notches or pawl-receiving recesses or openings42. Four openings 42 are shown but more may be desired in someinstallations.

The openings 42 are shown radially aligned with the pawls 21 such thatthe pawls may if outwardly projected engage the openings 42 topositively lock the impeller hub I2 in drive with the runner hub I8. Thepawls 21 are formed with an outer cammed surface 43 which is shaped suchthat when the pawls are urged outwardly by centrifugal force and theannular portion 4| of the runner hub I8 is rotated at a different speedthan the impeller hub I2, the surface 43 will engage the edge 44 of theopenings 42 and cam the pawls inwardly until the speeds of the twomembers are substantially synchronized, whereupon the pawls will enterthe openings 42.

In operation of the device so far described, let it be assumed that theparts are in-the position illustrated with the vehicle engine, hubs I2and I8, and the shaft 24 at rest. The engine may be started in thenormal manner and the vehicle may then be started, accelerated,maneuvered, etc., with the coupling elements slipping. When the vehiclehas been accelerated to a predetermined cruising speed, for example, 25M. P. I-I., the pawls 21 under the influence of centrifugal force, tendto move outwardly to They will be prevented from engaging the openings,however, so long as the rotative speeds of the pawls and the hub I8 aredifferent as they normally will be because of the slip between theimpeller and runner of the coupling. The driver can effect engagement ofthe pawls by momentarily releasing the engine throttle whereupon theimpeller will drop in speed relative to the runner and the pawls willengage at the instant of synchronism between these members.

Unless some means be provided for positively blocking or locking up thepawls under nonsynchronous conditions the pawls will ratchet by the pawlunits or openings 42 to produce a noisy operation and wear, and undercertain conditions even breakage of the pawls.

As a quickly acting means to positively block movement of the pawls intoengagement under non-synchronous conditions of operation I have providedas shown a balking or blocking ring in the nature of a flat ring 45carried on a shouldered annular flange 46 of the runner hub I8. Thisring lies between the flange 48 and the pawls 21. The forward face 41 ofthe ring 45 serves to hold the pawls endwise in position. The ring 45 isfurther provided with opposite lateral projections 48 formed at theperiphery of the ring 45 which are received and shown aligned withradial slots or wings 49 of a slotted portion in the pawls 21. The slots48 extend inwardly suicient to provide end clearance for the projection48 of the ring in the engaged position of the pwl 9W."

Wardly sufficiently to provide end clearance at the retracted positionof the pawls. As will be noted in Fig. 2, the pawls 41 are providedbetween the opposite ends of the radial slots 49 with intersectingcircumferential slots or wings 50 which extend on the nether side of theradial slots 49 and in the retracted position of the pawls shown in Fig.2 are circumierentially aligned with the projections 48 and are adaptedto receive the projection 48 of the balking ring 45 upon any relativerotation between pawls and ring 45. The pawls 21 are free for radialmovement by action of centrifugal force when the projection 48 is in theposition shown in the drawing at which time the pawl heads 33 andopenings 42 are also aligned. When, however, as in starting the vehiclefrom rest the impeller I0 is rotating faster than the runner such thatthe pawls will then also be rotating faster than the hub I8 of therunner the pawls will be rotating in the direction of the arrow in Fig.2 and the right hand portion of the slot 50 of the upper pawl in Fig. 2will embrace or engage the projections 48 of the balk ring 45 which isheld from rotation by the frictional drag between the ring and therunner hub I8 thereby preventing further outward movement of the pawl21. The slot 50 of the lower pawl will similarly engage the oppositeprojection 48 of the balk ring. Thereafter when the vehicle speed hasreached a predetermined value providing sufficient centrifugal force forengaging the pawls, momentary release of the throttle control to permitthe impeller to drop in speed relative to the runner and becomesynchronized therewith will effect a relative movement between the pawlsand the projections 48 whereby the slots 50 will become disengaged fromthe projections 48 and the pawls may then be projected outwardly intoengagement with the openings 42 of the runner hub I8. It will beunderstood that the flange portion 46 of the yhub I8 and inertia of thering 45 will impose a delaying action or drag on the ring 45 tofacilitate relative movement between the slots 50 of the pawls and theprojections 48.

The impeller and runner are now locked for conjoint operation withoutslippage so long as the impeller tends to overrun the runner as would bethe case during normal driving of the vehicle by the engine. When thevehicle speed is reduced below the engaging speed of the pawls thelatter will under urging by the springs 3U become disengaged from theopenings 42. At this time the runner and the ring 45 which it carrieswill tend to rotate at a greater speed than the impeller I0 and pawls 21thereby causing the projections 48 of the ring 45 to engage the lefthand (Fig. 2) portion of the slots 50 of the disengaged pawls which isthe opposite end from that engaged in effecting engagement of the pawlswhen speeding up the vehicle from rest. This engagement of theprojections 48 will prevent outward movement of the pawls should thecoast speed of the vehicle rise above the engaging speed of the pawlsdue to the driving of the pawls by the runner through the fluid of thecoupling. Should the coast speed be then decreased to permit synchronousrotation of the runner and impeller the projections 48 will leave theslots 50 and permit the pawls to engage the openings 42 of the hub I8 toprovide a positive drive under the coast operation of the vehicle.

It will be understood that I have provided a simple and desirableconstruction for retaining the pawls of a centrifugal clutch in apredetermined position until certain vehicle operating conditions havebeen reached in response to which such control means may release thepawls for engagement. Due to the juxtaposition of the projections 48 andopposite portions of the slots 50 the arrangement is quick acting inperforming the described functions.

While the particular structures herein described are well adapted forcarrying out the objects of the invention it will be understood thatvarious modifications, changes, and substitutions may be made withoutdeparting from the spirit thereof, for example, various changes in thesize, shape, and arrangement of the parts may be readily made by thoseskilled in the art. The present invention is, therefore, to be construedto include all such modifications, changes and substitutions.

I claim:

1. A power transmitting clutch mechanism comprising a driving member, adriven member, a centrifugally responsive pawl carried by one of saidmembers, an annular portion on said other member having an openingtherein for receiving said pawl at a predetermined rotative speed ofsaid one member and substantially synchronous rotation of said members,intersecting slots on said pawl forming oppositely aligned wings andmeans for preventing engagement of said pawl in said opening during allasynchronous rotation of said members comprising a ring having constantfrictional drive connection with said other member and having an axiallyextending lateral projection substantially paralleling the axis ofrotation of said other member adapted for engagement and movement insaid pawl slots.

2. A power transmitting clutch mechanism comprising a rotatable pawlcarrying core, a rotatable shell member having a pawl receiving recesstherein, a pawl carried by said core and movably responsive tocentrifugal force upon rotation of said core to engage said recess forestablishing a positive drive between said core and shell and means forpreventing engagement of said pawl during all asynchronous rotation ofsaid core and shell comprising a ring having frictional drive connectionwith said shell member, an axially extending lateral projection on saidring and slot means in said pawl for receiving said projection andpermitting relative oscillation between said ring and pawl said slotmeans including intersecting radial and circumferential slots havingoppositely aligned Wings.

3. A power transmitting clutch mechanism comprising a rotatable pawlcarrying core, a rotatable shell member having a pawl receiving recesstherein, a pawl carried by said core and movably responsive tocentrifugal force upon rotation of said core to engage said recess forestablishing a positive drive between said core and shell and means forpreventing engagement of said pawl during all asynchronous rotation ofsaid core and shell comprising a ring having constant frictional driveconnection with said shell member, a lateral projection on said ring anda pair of intersecting recesses in a face of said pawl for receivingsaid projection, one recess being adapted to receive said projectionduring all asynchronous rotation of said core and shell member and theother adapted to receive said projection during engaging movement ofsaid pawl.

4. A power transmitting clutch mechanism comprising a rotatable pawlcarrying core, a rotatable shell member having a pawl receiving recesstherein, a pawl carried by said core and Vmovably responsive tocentrifugal force upon rotation of said core to engage said recess forestablishing a positive drive between said core and shell and means forpreventing engagement of said pawl during asynchronous rotation of saidcore and shell comprising a ring having constant frictional driveconnectionwith said shell member, a laterally extending lug on said ringparalleling the core axis, a radially directed recess on said pawl forreceiving said lug and a second recess substantially normal to saidradial recess for receiving said lug said second recess cutting acrosssaid radial recess intermediate its length.

5. A power transmitting clutch mechanism as claimed in claim 2 whereinthere is a pair of oppositely movable pawls and wherein said ring hasdiametrically opposite lateral projections.

6. A power transmitting clutch mechanism comprising a driving member, adriven member, said driving member having a pawl carrying core, and saiddriven member having a cupshaped portion, the side wall of whichsurrounds said core, a pawl carried by said core and movably responsiveto centrifugal force upon rotation of said driving member, a recess insaid side wall of said cup-shaped portion for interengaging with saidpawl to establish a positive driving connection between said drive anddriven members, a shouldered face in the bottom of said cup, a balk ringmounted in frictional drive relationship to said face, a lug on saidring and a pair of intersecting recesses on said pawl for receiving saidlug said recesses crossing each other so as to have opposite alignedportions.

7. A power transmitting clutch mechanism comprising coaxial driving anddriven members, a centrifugally responsive pawl carried by one of saidmembers, an annular portion on said other member having a pawl receivingopening therein, a pawl blocking ring carried by said other member andhaving a constant frictional drive connection therewith, a lateralblocking lug on said ring extending toward said pawl-carrying member, aradial slot on said pawl for receiving said lug, said slot having alength permitting engaging and disengaging movement of said pawl and asecond slot on said pawl intersecting said rst mentioned slotintermediate the length of the latter. said second slot permittingrelative oscillatory movement between said pawl and ring and having stopabutments at the opposite ends thereof for limiting said relativemovement and for preventing engaging movement of said pawl with saidopening.

8. In a fluid power transmitting mechanism, having a vaned drivingelement, a vaned driven element, clutch means for effecting a positivedrive between said elements comprising a pair of centrifugallyresponsive pawls rotatably carried by one element, a slotted shellcarried by the other element adapted to receive a pawl to positivelyconnect said elements in drive, said pawls having lateral faces, andmeans to maintain disengagement of the pawls during iiuid drive of theelements and asynchronous rotation of said elements comprising a ring infrictional drive engagement with said other element, a lateralprojection on said ring and a slotted portion in a lateral face of apawl constantly engaging said projection, said slotted portion having aradial wing in which said projection may move when effecting engagementof the pawl and having circumferential wings on each side of said radialwing adapted to receive said projection during 7 all asynchronousrotation of said elements When below the engaging speed of said paWlwhereby to prevent engagement of the pawl with the shell undercontinuous asynchronous rotation of the elements to above the engagingspeed of the pawls.

9. A power transmitting clutch mechanism comprising a driving member, adriven member, a centrifugallyv responsive paWl carried by one of saidmembers, an annular portion on said other member having an openingtherein for receiving said pawl at a predetermined rotative speed ofsaid one member and substantially synchronous rotation of said membersand means for preventing engagement of said paWl in said opening duringall asynchronous rotation-ofsaid ymembers comprising a ring havingfrictional drive connection with said other member and having a lateralfinger-like projection substantially paralleling the axis of rotation ofsaid other member adapted for positive interengagement with a recessportion of said pawl when the pavvl is rotatably faster than said othermember or said other member is rotatably faster than said vpavvl.

EDWIN R. MAURER.

References Cited in the file of this patent UNITED STATES PATENTS

